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3 posts tagged with "erasure coding"

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· One min read
Joachim Kraftmayer

Create an erasure coded rbd pool

ceph osd pool create ec-pool 1024 1024 erasure 8-3
ceph osd pool set data01 allow_ec_overwrites true
rbd pool init ec-pool

note

Many things can be changed later in ceph during the runtime. However, the settings for the distribution of data and coding chunks must be defined when the EC pool is created. This means you should think carefully about what you plan to do with the pool in the future.

Create a erasure coded rbd image, in the EC data pool and for the metadata (OMAP objects) you need the replicated target-pool:

rbd create --size 25G --data-pool ec-pool/origin-image target-pool/new-image
rbd info target-pool/new-image

Sources

docs.ceph.com/en/latest/rados/operations/erasure-code/

· 2 min read
Joachim Kraftmayer

Perhaps someone has already thought about using EC (erasure coding) for ceph pools, so that the overhead for the secure storage of data is not too high. This was already a topic in many of the trainings we have held in recent years.

But what most people forget after creating EC pools is how to get all the information about an existing pool.

ceph osd pool ls

or

ceph osd pool ls detail

don't really give information about the configuration of erasure coding pools. However, there is a small option that lets ceph spill the beans a bit more.

ceph osd pool ls detail --format=json

you might get more information than you want.

But with

ceph osd pool ls detail --format=json | jq '.'

the whole thing looks much more friendly to the eyes.

And here we find more information about the erasure coded pools:

ceph osd pool ls detail --format=json | jq '.' | grep erasure_code_profile
erasure_code_profile": "clyso-costum-profile",

If you want to list all defined profiles, then use

ceph osd erasure-code-profile ls

You can get detailed information about an erasure code profile with:

ceph osd erasure-code-profile get clyso-costum-profile